CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Percentage	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues
Lime and limestone operations (as a percent)	96.90%	96.20%	96.30%	95.80%
Natural gas interests (as a percent)	3.10%	3.80%	3.70%	4.20%
Total revenues (as a percent)	100.00%	100.00%	100.00%	100.00%
Cost of revenues:
Labor and other operating expenses (as a percent)	65.20%	65.60%	65.20%	66.00%
Depreciation, depletion and amortization (as a percent)	9.50%	9.70%	9.50%	10.50%
Total cost of revenues (as a percent)	74.70%	75.30%	74.70%	76.50%
Gross profit (as a percent)	25.30%	24.70%	25.30%	23.50%
Selling, general and administrative expenses (as a percent)	6.20%	6.00%	6.10%	6.40%
Operating profit (as a percent)	19.10%	18.70%	19.20%	17.10%
Other expense (income):
Interest expense (as a percent)	0.90%	1.20%	1.00%	1.30%
Other, net (as a percent)	0.00%	0.20%	0.00%	0.00%
Total other expense (income) (as a percent)	0.90%	1.40%	1.00%	1.30%
Income before income taxes (as a percent)	18.20%	17.30%	18.20%	15.80%
Income tax expense (as a percent)	4.30%	4.30%	4.50%	4.00%
Net income (as a percent)	13.90%	13.00%	13.70%	11.80%